Commercial earth observation satellites, such as Ikonos and Geoeye-1, offer imagery of ground-based targets. These satellites typically offer multispectral (MSI) imaging, which provides images at red, green, blue, and near-infrared wavelengths, and panchromatic (PAN) imaging, which provides black-and-white images formed from wavelengths that span the visible spectrum. This imagery is commonly referred to as electro-optical (EO) imagery.
In many cases, the multispectral images show registration errors with respect to one another and with respect to 3D sources such as LADAR, a digital elevation model database, a system that generates 3D points from imagery, radar generated points, or another suitable sources. For instance, white vent covers on a non-white roof may not be aligned with their proper three-dimensional locations, or a LADAR point set from a sidewalk may be erroneously colored with the grass adjacent to it. These are but two specific examples; other registration errors are possible. These registration errors may complicate use of the multispectral images, and can introduce uncertainty in downstream applications that rely on the multispectral images to locate particular objects.
Laser Detection and Ranging (LADAR), typically obtained from aircraft that fly over the ground-based targets, can produce a three-dimensional profile of the targets. LADAR can produce a collection of points that represent the surface or surfaces of the targets, which is often referred to as a point cloud. Some 3D data sets obtained from LADAR can include additional intensity information corresponding to the location data. 3D data sets that include the intensity information can be used to form an image from which traditional 2D image-to-image registration techniques can be applied. However, some 3D data sets may lack the associated intensity information, and therefore cannot be used with the traditional image-to-image registration techniques.